Why do not cats cats drink any milk?



I think that there are many people who have been relieved by cat's agile and supple movement and occasional amazing balance feeling, but its elegance seems to be demonstrated even when drinking milk.

I admired the way the domestic cat moved quickly with my tongue and drink milk without spilling a drop without dirty hairMassachusetts Institute of TechnologyCivil engineers have worked with physicists and mathematicians of their colleagues about three and a half years to find out the wonder mechanisms by which cats drink milk without garging their jaws.

Details are as below.MIT - Study reveals the subtle dynamics underpinning how felines drink | Department of Civil & Environmental Engineering, MIT

The cat that licks liquid with a licking stick is to round the tip of the tongue to the back side like the letter of "J" and to attach it to the liquid from the front side of the tongue in advance, in 1940 MIT'sDr. Harold Edgerton(Milk crown photosFamous forElectronic flashWhenStroboscopeA leading photographer) was known for the slow motion image of the cat drinking milk taken by the cat. Incidentally, a short documentary containing images of this cat "Quicker'n a Wink"Was awarded the 1941 Academy Award.


However, MIT's Department of Civil and Environmental EngineeringRoman StockerAccording to the high speed picture taken by associate professors, it became clear that cats are touching milk only on the front side of the tongue, rather than pickling the tongue from the front to the top in the milk.

The cat does not scoop up the rounded tongue and scoop up the milk, it quickly touches the surface of the milk a little bit of the tongue and quickly raises it. A small milk pillar is formed between the milk body and the tongue that entered the vessel for a short time when the inertia working on the milk pulled up while sticking to the tongue is winning the gravity, inertial force loses gravity and the milk's Before the pillar sharply breaks, the cat closes its mouth pummy and captures the milk in the air. In the case of house cats it is said that this operation is repeated on average about four times per second.

Slow motion pictures taken by Professor Stocker and others are as follows.

YouTube - Cutta Cutta (12x slower)


Cutta Cutta (8 years old), a pet cat of Professor Stocker who became the origin of the research, in the model of the above video. The name "Cutta Cutta" isAboriginalThe word "star star" is the meaning of "star star" but it is a whimsical cat who is willing to keep a photographer waiting like a big star of silver screen, Professor Stocker and colleagues prepare milk in front of Cutta Cutta Even if you keep the camera, it seems that there were times when you did not drink until several hours.


Cutta Cutta owner, marine microorganismsBiophysicsDr. Stocker, Associate Professor at the Department of Civil Engineering and Environmental Engineering specializing in MIT and Associate Professor at the Department of Mechanical Engineering and Department of Civil Engineering and Environmental Engineering at MIT as well as physicists specializing in soft solid mechanicsPedro Miguel ReisDoctor,Virginia Tech UniversitySpecialize in biohydrodynamics atSunghwan JungDoctor,Princeton UniversityMathematicians specializing in the dynamics of liquid surface in the Department of Mechanical and Aerospace EngineeringJeff AristoffDr. Team consists of numerous, including Cutta CuttaYenecoShe seems to drink milk,Zoo New EnglandIn cooperation withFelidaeThe beast ofLion·Dora·Jaguar) Also shot high speed and analyzed the movement. Furthermore, I also analyzed the video of how the lion on YouTube drinking water and got the data, but I used the video of YouTube as research materialScienceIt is probably the first as a paper published in a magazine.

The following is the video of the lion.

YouTube - Male lions drinking at night


Dr. Stocker and others who got the pace to repeat the speed of movement of the tongue by analyzing these images photographed at high speed and the series of movements that touches and pulling the tongue with liquid,Froude numberBy a mathematical model using (a dimensionless number representing the ratio of the inertial force of the fluid to the gravity), both small and large lions drink with an exquisite balance in which the gravity acting on the liquid and the inertia pulling the liquid are in equilibrium I found out that there was.

"The amount of liquid that a cat can drink each time she closes her mouth depends on the size of the tongue and the speed with which the tongue moves.The results of this study suggest that each cat drinks around" lick " It suggests that you are optimizing the speed of moving the tongue to maximize the amount of liquid that can be made.In terms of fluid mechanics cats may be much smarter than people think "Dr. Aristoff says. A big cat such as a lion and a tiger seems to be licking at a slower pace than a domestic cat because of the large tongue size in order to balance inertia and gravity.

Dr. Stocker and colleagues also created a device to reproduce the movement of the tongue of the cat at various speeds and verified the hypothesis of "Optimization of tongue speed".

YouTube - Experiment (100x slower)


Dr. Sunghwan Jung, specializing in biohydrodynamics, said, "At the beginning of the project we were not yet convinced whether fluid dynamics would be involved in cats drinking water, but as the research progressed , I was impressed with the hydrodynamic beauty of the cat's drinking mechanism. "

In this research, in a certain sense as a scientific study of natural phenomena, which makes a hypothesis, observes and experiments, and answers by a mathematical model against the question felt by observing a certain phenomenon, it follows a traditional course It was that it was what it was.

"This project, which we started three and a half years ago, is not fundamental to research from national or sponsor companies, it does not mean that we can not use graduate students from laboratories, we do not use state-of-the-art equipment However, I was able to demonstrate teamwork and creativity skillfully.The science is work for me but also for my passion.The science shows the phenomenon we normally see unexpectedly from a different perspective It gives me an understanding of how things work, "says Dr. Stocker, owner of Cutta Cutta.

in Science,   Creature,   Video, Posted by darkhorse_log